#pragma GCC optimize(2)
#include <iostream>
#include <algorithm>
#include <cstring>
#include <string>
#include <map>
#include <vector>

using namespace std;
using LL = long long;

int main(){
    freopen("in.txt", "r", stdin);
    freopen("out.txt", "w", stdout);
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    char st = 'A';

    int k;
    cin >> k;
    for(int i = 0; i < k; i ++){
        char cur = (char)(st + i);
        cout << cur; 
    }


    return 0;
}